JPWO2019198744A1 - Maximum heart rate estimation method and device - Google Patents

Abstract

The maximum heart rate estimation method is based on the first acquisition step of acquiring the heart rate of the subject who exercises, the second acquisition step of acquiring the electrocardiographic waveform of the subject who exercises, and the acquired electrocardiographic waveform. Estimates including a third acquisition step of acquiring a predetermined feature amount and an estimation step of estimating the maximum heart rate of the subject based on the relationship between the predetermined feature amount and the acquired heart rate. The step estimates the subject's maximum heart rate based on the heart rate corresponding to the inflection point at a predetermined feature change with respect to the acquired heart rate.

Description

The present invention relates to a maximum heart rate estimation method and an apparatus, and more particularly to a technique for estimating a maximum heart rate using an electrocardiographic waveform.

In sports and daily life, managing heart rate makes it possible to estimate exercise intensity and calories. Exercise intensity using heart rate can generally be calculated by the Carbonen method (see, for example, Non-Patent Document 1). Therefore, it is necessary to measure or estimate the maximum heart rate in order to calculate the exercise intensity. In addition, since the value of exercise intensity is also required when calculating calories, it is important to measure or estimate the maximum heart rate.

Conventionally, when measuring the maximum heart rate, the amount of exercise is increased until the subject's heart rate reaches the maximum heart rate in a gradual load test or the like.

Jinhua She, Hitoshi Nakamura, Koji Makino, Hiroshi Hashimoto, "Selection of Suitable Maximum-heart-rate Formulas for Use with Karvonen Formula to Calculate Exercise Intensity", International Journal of Automation and Computing, 12 (1), February 2015, pp. 62-69. https: // ja. wikipedia. org / wiki / exercise intensity (searched on March 20, 2018) Shaffer, Fred, and J. et al. P. Ginsberg. "An overview of heart rate variability metric and norms." Frontiers in public health 5 (2017): 258 Hideaki Senju "Chapter 3 Exercise and Changes in Cardiopulmonary Function (Part I Regional Wellness Exercise)" Life and Community Health Promotion, Nagasaki University Open Lecture Series 7 (published March 5, 1995): pp. 31-39, <http: // dl. handle. net / 10069/6315>

However, in the conventional method of measuring the maximum heart rate by a gradual load test or the like, there is a problem that the burden on the subject is heavy.

The present invention has been made to solve the above-mentioned problems, and the maximum heart rate estimation that can estimate the maximum heart rate without requiring exercise until the subject's heart rate reaches the maximum heart rate. It is an object of the present invention to provide methods and devices.

In order to solve the above-mentioned problems, the maximum heart rate estimation method according to the present invention acquires the first acquisition step of acquiring the heart rate of the subject who exercises and the electrocardiographic waveform of the subject who exercises. Based on the second acquisition step, the third acquisition step of acquiring a predetermined feature amount from the acquired electrocardiographic waveform, and the relationship between the predetermined feature amount and the acquired heart rate. The estimation step comprises an estimation step for estimating the maximum heart rate of the subject, and the estimation step is based on the heart rate corresponding to the flexion point in the change of the predetermined feature amount with respect to the acquired heart rate. A method for estimating a maximum heart rate, which comprises estimating the maximum heart rate of a subject.

Further, the maximum heart rate estimation device according to the present invention acquires a heart rate acquisition unit that acquires the heart rate of the subject who exercises and an electrocardiographic waveform of the subject who exercises, and obtains the electrocardiographic waveform of the subject in advance from the electrocardiographic waveform. It is provided with a feature amount acquisition unit that acquires a predetermined feature amount, and an estimation unit that estimates the maximum heart rate of the subject based on the relationship between the acquired heart rate and the predetermined feature amount. The estimation unit is characterized in that the maximum heart rate of the subject is estimated based on the heart rate corresponding to the bending point in the change of the predetermined feature amount with respect to the acquired heart rate.

According to the present invention, from the relationship between the heart rate of the subject and the predetermined feature amount included in the electrocardiographic waveform of the subject, the maximum heart rate is based on the bending point in the change of the feature amount with respect to the heart rate. Is calculated, the maximum heart rate can be estimated without the need for exercise until the subject's heart rate reaches the maximum heart rate. Therefore, it is possible to reduce the burden on the subject when obtaining the maximum heart rate.

FIG. 1 is a diagram for explaining the principle of the present invention. FIG. 2 is a diagram for explaining the principle of the maximum heart rate estimation device according to the first embodiment of the present invention. FIG. 3 is a diagram for explaining the principle of the maximum heart rate estimation device according to the first embodiment of the present invention. FIG. 4 is a block diagram showing a functional configuration of the maximum heart rate estimation device according to the first embodiment of the present invention. FIG. 5 is a block diagram showing a hardware configuration of the maximum heart rate estimation device according to the first embodiment of the present invention. FIG. 6 is a flowchart for explaining the maximum heart rate estimation method according to the first embodiment of the present invention. FIG. 7 is a diagram for explaining the principle of the maximum heart rate estimation device according to the second embodiment of the present invention. FIG. 8 is a block diagram showing a functional configuration of the maximum heart rate estimation device according to the second embodiment of the present invention. FIG. 9 is a flowchart for explaining the maximum heart rate estimation method according to the second embodiment of the present invention. FIG. 10 is a diagram for explaining the principle of the maximum heart rate estimation device according to the third embodiment of the present invention. FIG. 11 is a block diagram showing a functional configuration of the maximum heart rate estimation device according to the third embodiment of the present invention. FIG. 12 is a flowchart for explaining the maximum heart rate estimation method according to the third embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS. 1 to 12.
[Principle of invention]
FIG. 1 is a diagram showing an electrocardiographic waveform. The maximum heart rate estimation method according to the embodiment of the present invention extracts a predetermined feature amount as an index of the maximum heart rate from the electrocardiographic waveform of the subject, and for example, obtains the maximum heart rate for obtaining exercise intensity. To estimate. Exercise intensity is a measure of the intensity of exercise based on the physical ability of the subject who exercises.

In the maximum heart rate estimation method according to the present embodiment, QT representing the time from the start of the Q wave to the end of the T wave among the characteristic waveforms and waveform intervals included in the electrocardiographic waveform shown in FIG. The interval is used as a feature of the electrocardiographic waveform (electrocardiogram).

FIG. 2 is a diagram showing the relationship between the exercise intensity obtained by the gradual load test and the QT interval. In the present embodiment, a value calculated from the heart rate (Heart Rate: HR) is used as the exercise intensity. As shown in FIG. 2, it can be seen that a bending point is seen in the graph near the exercise intensity of 40%. From this experiment, it was found that the heart rate at the flexion point was about 40% of the exercise intensity.

It is considered that the results of this experiment are almost the same as the relationship between the amount of one stroke and the change in cardiac output due to exercise described in Non-Patent Document 4. In general, exercise increases the oxygen requirement of peripheral tissues such as muscle. As described in Non-Patent Document 4, the stroke volume (SV), which is the amount of blood pumped by one contraction of the heart, increases at a constant rate as the exercise intensity increases. It is known that after the exercise intensity increases to about 40% of the maximum exercise intensity, it does not increase and reaches a plateau. Therefore, in exercise in which the exercise intensity exceeds about 40%, the cardiac output (CO), which is the amount of blood pumped from the heart per minute, is supplemented by the increase in the heart rate.

From this, it is considered that the maximum heart rate can be estimated by using the above-mentioned experimental results with the heart rate at the bending point of the QT interval as the exercise intensity of 40%.
Here, the maximum heart rate is calculated by the following formula (1) (see, for example, Non-Patent Document 2).
Maximum heart rate = resting heart rate + 100 x (heart rate at the flexion point-heart rate at rest) / exercise intensity at the flexion point ... (1)
In the above equation (1), the "resting heart rate" is a value measured in advance at rest with a heart rate monitor or the like. Generally, a resting heart rate of 60 bpm is used. The “heart rate at the flexion point” is the value of the measured heart rate corresponding to the flexion point of the QT interval. Further, the "exercise intensity serving as a bending point" is a preset value, and a value in the range of 35 to 45%, for example, 40% is used based on the above-mentioned experimental results.

FIG. 3 shows the result when the maximum heart rate is estimated using the above equation (1). In FIG. 3, the vertical axis is the maximum heart rate estimated by the method for estimating the maximum heart rate according to the present embodiment, and the horizontal axis is the maximum measured by exercising until the subject's heart rate reaches the maximum heart rate. Heart rate.

As shown in FIG. 3, the correlation coefficient (Pearson correlation function) was 0.78, the p-value was <0.05, and it was found that there was a significant positive correlation. From this, the maximum heart rate estimation method according to the present embodiment finds a point where the QT interval bends in the relationship between the QT interval and the heart rate, and calculates the maximum heart rate by using the above equation (1). To do.

[First Embodiment]
Hereinafter, the maximum heart rate estimation device 1 for carrying out the maximum heart rate estimation method according to the present invention will be described in detail.
FIG. 4 is a block diagram showing a functional configuration of the maximum heart rate estimation device 1 according to the first embodiment. The maximum heart rate estimation device 1 includes a biological information acquisition unit 11, a storage unit 12, an estimation unit 13, and an output unit 14.

The maximum heart rate estimation device 1 acquires the relationship between the QT interval and the heart rate when the subject performs an exercise that gradually increases the exercise intensity, such as a gradual load test, and determines that the value of the QT interval bends. The maximum heart rate of the subject is calculated from the inflection point.

The biological information acquisition unit 11 includes a heart rate acquisition unit 111 and a QT interval acquisition unit 112.
The biological information acquisition unit 11 acquires information on the heartbeat and electrocardiogram of the subject from an external heart rate monitor attached to the subject and a biosensor (not shown) having the function of the electrocardiograph. At this time, from the above-mentioned experimental results, the biological information acquisition unit 11 relates to the heartbeat and the electrocardiogram during the period from when the subject starts the exercise to gradually increase the exercise intensity until the exercise intensity exceeds 40%. All you have to do is get the information.

The heart rate acquisition unit 111 acquires the heart rate over the period during which the subject exercises from the biosensor attached to the subject. The acquired heart rate data is stored in the storage unit 12.

The QT interval acquisition unit 112 acquires the QT interval included in the electrocardiographic waveform from the electrocardiographic waveform measured by the biosensor worn on the subject. The QT interval acquired by the QT interval acquisition unit 112 is stored in the storage unit 12.

The storage unit 12 stores the data of the heart rate and the QT interval of the subject acquired by the biological information acquisition unit 11. In addition, the storage unit 12 stores the set values of "resting heart rate" and "exercise intensity serving as a flexion point" in the above-mentioned formula (1).

The estimation unit 13 includes an inflection point processing unit 131 and a maximum heart rate calculation unit 132.
The estimation unit 13 estimates the maximum heart rate based on the heart rate and QT interval data of the subject acquired by the biological information acquisition unit 11.

The inflection point processing unit 131 reads the heart rate data of the subject acquired by the heart rate acquisition unit 111 and the QT interval data of the subject acquired by the QT interval acquisition unit 112 from the storage unit 12, and reads the QT interval. And the relationship between heart rate and heart rate. At this time, a graph including the bending points as shown in FIG. 2 is obtained.

Further, the bending point processing unit 131 extracts the bending point in the change of the QT interval with respect to the heart rate acquired by the heart rate acquisition unit 111 from the relationship between the QT interval and the heart rate in the subject. The bending point processing unit 131 obtains the heart rate of the subject corresponding to the point at which the value of the QT interval bends and stores it in the storage unit 12.

The maximum heart rate calculation unit 132 calculates the maximum heart rate of the subject by the above equation (1) based on the heart rate of the subject at the flexion point extracted by the flexion point processing unit 131.
More specifically, the maximum heart rate calculation unit 132 substitutes the value of the “heart rate serving as the flexion point” obtained by the flexion point processing unit 131 in the equation (1) into the equation (1). The value of the "resting heart rate" in the formula (1) is a preset value, for example, 60 bpm, and the value of the "exercise intensity at the bending point" is a preset value, for example, 40. % Is used.

The maximum heart rate calculation unit 132 stores the calculated maximum heart rate value of the subject in the storage unit 12.

The output unit 14 outputs information such as the maximum heart rate of the subject estimated by the estimation unit 13. More specifically, the output unit 14 displays the value of the maximum heart rate calculated by the maximum heart rate calculation unit 132 on a display screen or the like.

[Hardware configuration of maximum heart rate estimation device]
Next, the hardware configuration of the maximum heart rate estimation device 1 having the above-mentioned functional configuration will be described with reference to the block diagram of FIG.

As shown in FIG. 5, the maximum heart rate estimation device 1 includes an arithmetic unit 102, a communication control device 105, a sensor 106, an external storage device 107, and a display having a CPU 103 and a main storage device 104 connected via a bus 101. This can be achieved by a computer equipped with the device 108 and a program that controls these hardware resources.

The CPU 103 and the main storage device 104 form an arithmetic unit 102. A program for the CPU 103 to perform various controls and calculations is stored in the main storage device 104 in advance. The arithmetic unit 102 realizes the function of the maximum heart rate estimation device 1 including the estimation unit 13 shown in FIG.

The communication control device 105 is a control device for connecting the maximum heart rate estimation device 1 and various external electronic devices via the communication network NW. The communication control device 105 may receive heart rate and electrocardiographic waveform data from the sensor 106, which will be described later, attached to the subject via the communication network NW.

The sensor 106 is realized by a biosensor such as a heart rate monitor and an electrocardiograph, for example. The sensor 106 is attached to, for example, the chest or wrist of the subject during the period during which the subject exercises, and measures the heart rate and the electrocardiographic waveform of the subject. For example, a sensor 106 mounted on the chest measures an electrocardiographic waveform with electrodes (not shown), detects a heartbeat from the change, and determines the number of beats per minute from the interval between heartbeats. Measure as.

The external storage device 107 is composed of a readable and writable storage medium and a drive device for reading and writing various information such as programs and data to the storage medium. A semiconductor memory such as a hard disk or a flash memory can be used as the storage medium in the external storage device 107. The external storage device 107 is a data storage unit 107a, a program storage unit 107b, and other storage devices (not shown). For example, a storage device for backing up programs and data stored in the external storage device 107. Can have.

The data storage unit 107a stores information on the electrocardiographic waveform and heart rate of the subject measured by the sensor 106. The data storage unit 107a corresponds to the storage unit 12 shown in FIG.

The program storage unit 107b contains various programs for executing processing necessary for estimating the maximum heart rate, such as heart rate and QT interval acquisition processing, flexion point processing, and maximum heart rate calculation processing in the present embodiment. It is stored.

The display device 108 constitutes the display screen of the maximum heart rate estimation device 1 and functions as the output unit 14. The display device 108 is realized by a liquid crystal display or the like.

[Operation of maximum heart rate estimation device]
Next, the operation of the maximum heart rate estimation device 1 for carrying out the above-described maximum heart rate estimation method of the present invention will be described with reference to the flowchart of FIG. First, a biosensor having the functions of a heart rate monitor and an electrocardiograph (not shown) is attached to the subject's chest, wrist, etc., and the subject starts an exercise such as a gradual load test in which the exercise intensity gradually increases. .. The heart rate and electrocardiographic waveform of the subject are measured by the biosensor over a period from the start of the exercise until the exercise intensity in the subject exceeds 40%.

The heart rate acquisition unit 111 acquires heart rate data while the subject performs exercise (step S1). Next, the QT interval acquisition unit 112 acquires the data of the electrocardiographic waveform while the subject performs the exercise, and acquires the data of the QT interval from the data of the electrocardiographic waveform (step S2). The QT interval acquisition unit 112 may adopt a configuration that acquires the value of the QT interval obtained by an external biosensor.

Next, the inflection point processing unit 131 obtains the relationship between the acquired QT interval and the heart rate (step S3). In the relationship between the QT interval of the subject and the heart rate obtained by the bending point processing unit 131, the bending point at which the value of the QT interval bends is extracted, and the heart rate corresponding to the value of the QT interval is obtained (step S4). ..

Next, the maximum heart rate calculation unit 132 calculates the maximum exercise intensity of the subject using the above equation (1) based on the heart rate that is the bending point of the measured value of the QT interval obtained in step S4. (Step S5).

More specifically, the maximum heart rate calculation unit 132 uses a value such as a value actually measured in advance as the value of the "resting heart rate" in the equation (1), for example, 60 bpm. The maximum heart rate calculation unit 132 substitutes the measured value of the heart rate obtained in step S4 as the value of the “heart rate serving as the bending point”. Further, as the value of "exercise intensity serving as a bending point", a value in a predetermined range of 35 to 45% from the above-mentioned experimental results, for example, 40% is used.

The calculated maximum exercise intensity of the subject is output by the output unit 14.

As described above, according to the first embodiment, the bending point of the QT interval observed in the vicinity where the exercise intensity (heart rate) becomes 40% using the relationship between the QT interval and the heart rate of the subject. Estimate the maximum heart rate based on the subject's heart rate in. Therefore, if the exercise intensity exceeds 40%, the maximum heart rate can be estimated without requiring the exercise until the subject's heart rate reaches the maximum heart rate. Therefore, it is possible to reduce the burden on the subject when obtaining the maximum heart rate.

Further, in the first embodiment described, the case where the QT interval is acquired from the measured electrocardiographic waveform of the subject has been described. However, as the feature amount of the electrocardiographic waveform, the RT interval, which is the time from the start of the R wave to the end of the T wave included in the electrocardiographic waveform shown in FIG. 1, may be used instead of the QT interval. By using the RT interval, it is possible to more easily acquire the feature amount corresponding to the QT interval.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. In the following description, the same components as those in the first embodiment described above will be designated by the same reference numerals, and duplicate description will be omitted.

In the first embodiment, the QT interval observed in the vicinity where the exercise intensity (heart rate) becomes about 40% based on the relationship between the QT interval and the heart rate measured during the period during which the subject exercises. The heart rate corresponding to the inflection point of the value was obtained, and the maximum heart rate of the subject was calculated. On the other hand, in the second embodiment, the height of the T wave included in the electrocardiographic waveform of the subject is used as the feature amount of the electrocardiographic waveform.

First, the outline of the maximum heart rate estimation device 1A according to the second embodiment will be described with reference to FIG. 7. The horizontal axis of the graph shown in FIG. 7 indicates the exercise intensity converted into heart rate. The vertical axis indicates the value obtained by multiplying the height of the T wave in the electrocardiographic waveform of the subject by the heart rate (T wave height × heart rate).

As shown in FIG. 7, it can be seen that a bending point is also observed in the vicinity of the exercise intensity (heart rate) of 40% in the T wave height × heart rate of the electrocardiographic waveform. From this, by obtaining the measured heart rate corresponding to the bending point, the maximum heart rate of the subject can be calculated by using the equation (1) as in the first embodiment.

Next, the functional configuration of the maximum heart rate estimation device 1A according to the present embodiment will be described focusing on a configuration different from that of the first embodiment.
The biological information acquisition unit 11A includes a heart rate acquisition unit 111 and a T wave height acquisition unit 113.

The T-wave height acquisition unit 113 acquires an electrocardiographic waveform from a biosensor worn on the subject, and acquires data on the T-wave height included in the electrocardiographic waveform. The T wave height data acquired by the T wave height acquisition unit 113 is stored in the storage unit 12.

The inflection point processing unit 131 multiplies the T wave height value acquired by the T wave height acquisition unit 113 of the biological information acquisition unit 11A by the heart rate value of the subject acquired by the heart rate acquisition unit 111. Calculate T wave height x heart rate. Further, the inflection point processing unit 131 obtains the relationship between the T wave height × heart rate and the measured value of the heart rate of the subject acquired by the heart rate acquisition unit 111.

In the bending point processing unit 131, the value of T wave height × heart rate bends in the vicinity of exercise intensity (heart rate) of 40% in the relationship between the obtained T wave height × heart rate and heart rate of the subject. Find a point. The inflection point processing unit 131 obtains the heart rate corresponding to the inflection point. The obtained heart rate value is stored in the storage unit 12.

Next, the operation of the maximum heart rate estimation device 1A having the above-described configuration will be described with reference to the flowchart of FIG.
First, as in the first embodiment, a biosensor having a heart rate monitor and an electrocardiograph function (not shown) is attached to the chest, wrist, or the like of the subject, and the subject gradually exercises as in a gradual load test. Start exercising to increase intensity. The heart rate and electrocardiographic waveform of the subject are measured by the biosensor over a period from the start of the exercise until the exercise intensity of the exercise performed by the subject exceeds 40%.

The heart rate acquisition unit 111 acquires heart rate data over a period during which the subject exercises (step S21). Next, the T wave height acquisition unit 113 acquires T wave height data from the electrocardiographic waveform data over the period during which the subject exercises (step S22). The T-wave height acquisition unit 113 may adopt a configuration for acquiring T-wave height data obtained on the biosensor side.

Next, the inflection point processing unit 131 obtains the relationship between the acquired T wave height × heart rate and the heart rate (step S23). After that, the inflection point processing unit 131 extracts an inflection point at which the value of T wave height × heart rate bends in the relationship between the obtained T wave height × heart rate and heart rate of the subject, and the T wave height × The heart rate value corresponding to the heart rate value is obtained (step S24).

Next, the maximum heart rate calculation unit 132 uses the above equation (1) based on the heart rate which is the inflection point of the T wave height × heart rate value obtained in step S24, and the maximum exercise of the subject. The strength is calculated (step S25).

More specifically, the maximum heart rate calculation unit 132 uses a value actually measured in advance as the value of the "resting heart rate" in the equation (1), for example, 60 bpm. The maximum heart rate calculation unit 132 substitutes the heart rate obtained in step S24 as the value of the “heart rate serving as the bending point”. Further, as the value of "exercise intensity serving as a bending point", a predetermined value, for example, a value in the range of 35 to 45% such as 40% is used from the above-mentioned experimental results.

The calculated maximum exercise intensity of the subject is output by the output unit 14.

As described above, according to the second embodiment, using the relationship between the T wave height of the subject and the heart rate and the heart rate, the T observed in the vicinity of the exercise intensity (heart rate) of 40%. The maximum heart rate is estimated based on the subject's heart rate at the inflection point of wave height x heart rate. Therefore, even when the height of the T wave is used as the feature amount of the electrocardiographic waveform, if the exercise intensity exceeds 40%, the subject's heart rate reaches the maximum heart rate. Maximum heart rate can be estimated without the need for exercise. Therefore, it is possible to reduce the burden on the subject when obtaining the maximum heart rate.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. In the following description, the same components as those in the first and second embodiments described above will be designated by the same reference numerals, and duplicate description will be omitted.

In the first and second embodiments, based on the relationship between the heart rate measured during the period during which the subject exercises and the features such as the QT interval and T wave height observed in the electrocardiographic waveform. The maximum heart rate of the subject was calculated from the heart rate corresponding to the inflection point of the feature amount observed in the vicinity of the exercise intensity of about 40%. On the other hand, in the third embodiment, the root mean square of sensive differentials (rMSSD), which is a heart rate variability parameter known as an index of autonomic nerves, is used as a feature amount.

First, an outline of the maximum heart rate estimation method according to the third embodiment will be described with reference to FIG.
FIG. 10 is a diagram illustrating the relationship between rMSSD and exercise intensity. The vertical axis represents rMSSD, and the horizontal axis represents heart rate-equivalent exercise intensity.

Here, rMSSD is the square root of the square root of the square of the difference between the intervals of consecutively adjacent RR waves in the electrocardiographic waveform, and is known as an index relating to the autonomic nerve. As can be seen from FIG. 10, also in the relationship between the rMSSD and the exercise intensity, there is a point that the value of the rMSSD bends near the exercise intensity of 40%.

From this, the maximum heart rate of the subject is calculated by the above-mentioned equation (1) using the value of rMSSD as the feature amount of the electrocardiographic waveform.

Next, the functional configuration of the maximum heart rate estimation device 1B for carrying out the maximum heart rate estimation method according to the present embodiment will be described focusing on configurations different from those of the first and second embodiments.
As shown in FIG. 11, the biological information acquisition unit 11B includes a heart rate acquisition unit 111 and an rMSSD acquisition unit 114.

The rMSSD acquisition unit 114 acquires an electrocardiographic waveform from a biosensor worn on the subject, and acquires data on the interval between adjacent RR waves included in the electrocardiographic waveform. Further, the rMSSD acquisition unit 114 calculates the rMSSD based on the data indicating the interval of the acquired RR waves. The rMSSD value of the subject calculated by the rMSSD acquisition unit 114 is stored in the storage unit 12.

The inflection point processing unit 131 obtains the relationship between the heart rate of the subject acquired by the heart rate acquisition unit 111 and the rMSSD of the subject acquired by the rMSSD acquisition unit 114. The bending point processing unit 131 extracts the point at which the value of rMSSD bends in the relationship between the obtained rMSSD and the heart rate of the subject. The inflection point processing unit 131 obtains the heart rate corresponding to the inflection point. The obtained heart rate value is stored in the storage unit 12.

Next, the operation of the maximum heart rate estimation device 1B having the above-described configuration will be described with reference to the flowchart of FIG.
First, as in the first and second embodiments, the heart rate acquisition unit 111 performs an exercise in which the exercise intensity gradually increases, such as a gradual load test, and the exercise intensity exceeds 40%. The measured value of the heart rate up to the degree is acquired (step S31).

Next, the rMSSD acquisition unit 114 acquires data indicating the interval of the RR wave from the electrocardiographic waveform sent from the biosensor attached to the subject, and calculates the rMSSD (step S32). The rMSSD acquisition unit 114 may adopt a configuration that acquires the value of rMSSD calculated by an external biosensor.

Next, the inflection point processing unit 131 obtains the relationship between the heart rate of the subject acquired by the heart rate acquisition unit 111 and the rMSSD of the subject acquired by the rMSSD acquisition unit 114 (step S33).

After that, the bending point processing unit 131 finds a bending point at which the value of rMSSD bends in the relationship between the obtained rMSSD and the heart rate of the subject, and obtains the value of the heart rate corresponding to the value of the rMSSD (step S34). ).

Next, the maximum heart rate calculation unit 132 calculates the maximum exercise intensity of the subject using the above equation (1) based on the heart rate that is the bending point of the rMSSD value obtained in step S34 (1). Step S35).

More specifically, the maximum heart rate calculation unit 132 uses a value actually measured in advance as the value of the "resting heart rate" in the equation (1), for example, 60 bpm. The maximum heart rate calculation unit 132 substitutes the heart rate obtained in step S34 as the value of the “heart rate serving as the bending point”. Further, as the value of "exercise intensity serving as a bending point", a preset value, for example, a value in the range of 35 to 45% such as 40% is used from the above-mentioned experimental results.

The calculated maximum exercise intensity of the subject is output by the output unit 14.

As described above, according to the third embodiment, using the relationship between the subject's rMSSD and the heart rate, the subject's heart rate at the flexion point of the rMSSD observed in the vicinity of the exercise intensity of 40%. Estimate maximum heart rate based on numbers. Therefore, even when rMSSD is used as a feature in the electrocardiographic waveform, if the exercise intensity exceeds 40%, it is necessary to exercise until the subject's heart rate reaches the maximum heart rate. The maximum heart rate can be estimated without. Therefore, it is possible to reduce the burden on the subject when obtaining the maximum heart rate.

Further, in the present embodiment, the maximum heart rate of the subject is estimated by focusing on rMSSD which is an index of autonomic nerve, but another autonomic nerve index can be used instead of rMSSD. Therefore, it is possible to estimate the maximum heart rate with higher flexibility. Examples of other autonomic indicators include frequency domain LF value, HF value, LF / HF ratio, time domain Standard Deviation of the NN Intervals (SDNN), NN50, and pNN50 (eg, non-patented). Reference 3).

Although the method for estimating the maximum heart rate and the embodiment in the maximum heart rate estimation device of the present invention have been described above, the present invention is not limited to the described embodiments and is within the scope of the invention described in the claims. It is possible to make various modifications that can be imagined by those skilled in the art.

In the above-described embodiment, a case where the subject performs an exercise such as a gradual load test and data on the heart rate and the electrocardiographic waveform over the period of the exercise is acquired has been described. However, the exercise performed by the subject does not have to be a controlled exercise such as a gradual load test, and the relationship between the feature amount such as the QT interval and the heart rate is acquired from arbitrary exercise data and becomes a bending point. The maximum heart rate may be estimated by obtaining the heart rate.

1, 1A, 1B ... Maximum heart rate estimation device, 11, 11A, 11B ... Biometric information acquisition unit, 12 ... Storage unit, 13 ... Estimate unit, 14 ... Output unit, 111 ... Heart rate acquisition unit, 112 ... QT interval acquisition Unit, 113 ... T wave height acquisition unit, 114 ... rMSSD acquisition unit, 131 ... flexion point processing unit, 132 ... maximum heart rate calculation unit, 101 ... bus, 102 ... arithmetic unit, 103 ... CPU, 104 ... main storage device, 105 ... communication control device, 106 ... sensor, 107 ... external storage device, 107a ... data storage unit, 107b ... program storage unit, 108 ... display device, NW ... communication network.

Claims (8)

The first acquisition step to acquire the heart rate of the subject who exercises,
The second acquisition step of acquiring the electrocardiographic waveform of the subject who exercises, and
A third acquisition step of acquiring a predetermined feature amount from the acquired electrocardiographic waveform, and
An estimation step for estimating the maximum heart rate of the subject based on the relationship between the predetermined feature amount and the acquired heart rate, and
With
The estimation step is characterized in that the maximum heart rate of the subject is estimated based on the heart rate corresponding to the flexion point in the change of the predetermined feature amount with respect to the acquired heart rate. Number estimation method. In the method for estimating the maximum heart rate according to claim 1,
The heart rate acquired in the first acquisition step and the electrocardiographic waveform acquired in the second acquisition step have different exercise intensities after the subject starts an exercise in which the exercise intensity increases. A method for estimating maximum heart rate, characterized in that it is acquired over a period of up to over 40%. In the method for estimating the maximum heart rate according to claim 1 or 2.
The maximum heart rate estimation method, wherein the predetermined feature amount is a QT interval included in an electrocardiographic waveform. In the method for estimating the maximum heart rate according to claim 1 or 2.
The maximum heart rate estimation method, wherein the predetermined feature amount is the height of a T wave included in the electrocardiographic waveform. In the method for estimating the maximum heart rate according to claim 1 or 2.
A method for estimating a maximum heart rate, wherein the predetermined feature amount is an index related to an autonomic nerve included in the electrocardiographic waveform. In the method for estimating the maximum heart rate according to any one of claims 1 to 5.
In the estimation step, the maximum heart rate = resting heart rate + 100 × (heart rate at the flexion point-heart rate at rest) / exercise intensity at the flexion point (however, the resting heart rate is the heart rate measured in advance at rest). The maximum heart rate estimation is characterized in that the maximum heart rate is estimated using the heart rate corresponding to the flexion point and the exercise intensity at the flexion point as a preset value). Method. A heart rate acquisition unit that acquires the heart rate of the person performing the exercise,
A feature amount acquisition unit that acquires an electrocardiographic waveform of the subject who performs exercise and acquires a predetermined feature amount from the electrocardiographic waveform, and a feature amount acquisition unit.
An estimation unit that estimates the maximum heart rate of the subject based on the relationship between the acquired heart rate and the predetermined feature amount, and
With
The estimation unit estimates the maximum heart rate of the subject based on the heart rate corresponding to the inflection point in the change of the predetermined feature amount with respect to the acquired heart rate. Number estimator. In the maximum heart rate estimation device according to claim 7.
The heart rate acquired by the heart rate acquisition unit and the electrocardiographic waveform acquired by the feature amount acquisition unit have different exercise intensities after the subject starts an exercise in which the exercise intensity increases. A maximum heart rate estimator, characterized in that it is acquired over a period of up to over 40%.

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